1. Field of the Invention
The present invention relates to a resectoscope apparatus and an electric operation apparatus which incise, resect, and transpire the body tissue through electric resection under an endoscope.
2. Description of the Related Art
Generally, a resectoscope is used for transurethral resection (TUR) and transcervical resection (TCR), and mainly comprises an optical scope (also referred to as a scope) as an endoscope for observation and an electrode unit for resecting the anatomy in an elongated and hollow sheath inserted in the celom.
The resectoscope apparatus includes two types of one for treatment in a non-conductive solution and one for treatment in a conductive solution.
Upon treatment such as the prostatectomy by using the resectoscope apparatus for treatment in the non-conductive solution, the space is expanded by supplying D-sorbitol as an insulative transparent solution corresponding to perfusate for expanding the narrow space and the sheath of the resectoscope is inserted into the space. High-frequency current is energized to a treatment electrode of the electrode unit arranged to the opening of a distal end portion of the sheath while observing a surface of the lesion portion by using the scope arranged in the sheath. The high-frequency current flows to a counter-electrode plate as an external electrode arranged to the outside of the body via the anatomy from the treatment electrode. An operator advances or returns the treatment electrode by operating an operating unit for the treatment of the lesion portion.
In the case of the prostatectomy by using the resectoscope apparatus for treatment in the conductive solution, physiological saline or the like is used for the perfusate as the conductive solution. In the technology disclosed in Japanese unexamined Patent Application Publication No. 2000-201946, a return electrode is arranged near the distal end portion of the elongated and hollow sheath inserted in the celom filled with a conductive solution and the high-frequency current from the treatment electrode is collected via the return electrode.
In the conventional treatment using the return electrode under the conductive solution, bubbles of the conductive solution is generated around the return electrode by energizing the return electrode. The bubbles cover the entire circumference of the electrode and then electric resistance sharply increases between the electrode and the physiological saline and the anatomy and a high voltage is generated, thus to cause the discharging operation. Heat generated due to the discharge operation enables resection, transpiration, and coagulation due to the discharging operation, of the anatomy.
In the resectoscope apparatus using the non-conductive solution, current is concentrated near a metal such as a metal bolt which is implanted in the patient body and the nearby anatomy is baked and the current flows to the nerve in the body. Thus, the patient body reflexively moves and the operator cannot perform the operation. This problem is not caused in the resectoscope apparatus using the conductive solution.
However, in both the above resectoscope apparatuses, the high-frequency current is supplied by turning on a switch of a foot switch by the operator at a certain timing (t0), as shown in FIG. 26, so that the supply power is equal to a constant current value PP (watt) which is predetermined. FIG. 26 is a diagram for explaining a status for supplying power to the resectoscope apparatus.
The constant power value PP is equal to or more than a power value necessary for the treatment for the resection of the anatomy, and the high power equal to or more than the power necessary for the treatment is actually set as output power.